Tagged Questions

A database structure that can improve the speed of queries at the cost of disk space and slower inserts/updates. It stores a copy of one or more columns but structures the data differently to allow for faster access.

I'm trying to think through a setup with a central mariaDB instance (A) accessing data on physically remote servers (B).
All queries to the database (A) can be answered from indices only. Indices are ...

I have a table, which has two columns say A and B as part of the Primary index PI_AB.
I have to alter the length of B column - increase it.
I was planning to alter the primary index to just have A, ...

I am using Mongo Replica set and it seems to be working fine but when i check db.serverStatus i saw that there are lots of accessesNotInMemory for all The DBs in my mongo instance.
I checked MY RAM ...

I have a full text index defined as 'Automatic' radio button checked on in its Catalog. When I modify a word in the full text indexed column, the new word appears in the sys.dm_fts_index_keywords but ...

I use Postgres as my Database.As part of my project I am trying to Index adviser for Postgres which suggests indexes automatically to the queries running slow .
As far as I know only "EDB" has done ...

I'm new to PostgreSQL. I'm currently working on an open source software package which is java based using postgresql 9.3.
For some requirement I populated a table (organisationunit) without using the ...

In PostgreSQL data is first written to WAL files. When commit is done, data is written to WAL files and then return to client (synchronous commit). When checkpoint reached or WAL buffer becomes full, ...

A clustered index will sort row data in a table according to the ordering of the fields in the index. If so, why would you (or would you not) want to create a clustered index on the child table in a ...

I have a big database (200GB+) that contains some log info. And I want to speed up SELECT queries and stored procedures. I have a table with a GeneratedOnUtc datetime column, and have a non-clustered ...

I have a table which is 170 GB and it has 98 GB of free/empty space. The free space was created by a massive deletion. If I run DBCC REINDEX or ALTER INDEX REBUILD, will the index use that free space ...

I have a 170 GB table in a database. It has 70% fragmentation on its index (index has multiple columns in it). The last time I tried DBCC REINDEX the transaction log blew up in the hundreds of GBs.
...

I have a legacy schema (disclaimer!) that uses a hash-based generated id for the primary key for all tables (there are many). An example of such an id is:
922475bb-ad93-43ee-9487-d2671b886479
There ...

I have a large MySQL InnoDB table containing around 137 million rows.
I need to add a unique constraint to the table. We have two options:
1) A combination index on three columns, one of which will ...

Disclaimer: I am relatively new to PostgreSQL.
I'm wondering how to optimize a query that does 2 INNER JOINs. My scenario is fairly simple:
Select Posts with a photo (Posts.photo IS NOT NULL) and a ...

We been running ola hallengren Index Maintenance script and was ran into a problem with some indexes that have GUID as the Index Key, They are Frag and have a page count of 6,309, but they don’t get ...

My table has 981 million rows and is about 30GB large. It is six columns: ID, Ticker, Date, Time, Price, Volume. The data was in text files and using LOAD DATA INFILE was actually quite painless and ...

I took a copy of the current database from a live slave using pg_basebackup and recovered it to a brand new isolated computer following the instructions in the docs. Once the new database had started ...